The use of material deposition processes to coat the edges of razor blades with different materials is known as disclosed in U.S. Pat. Nos. 5,142,785 and 5,232,568. As disclosed in those patents, a vacuum chamber has a carousel with a vertical axis of rotation that is parallel to a vertical work holding surface. A stack of razor blades is mounted on the work holding surface such that the longitudinal edges of the razor blades are generally parallel to the direction of motion of the work holding surface. The razor blades are moved to a first fixed position in which the blade edges are directly in front of and generally parallel to a first sputter target. Power is applied to the sputter target to deposit a thin molybdenum layer on the edges and the sides of the blade edges. The blades are then rotated approximately 90.degree. and stopped at a second position directly in front of a second target which is generally parallel to the blade edges. Power is applied to the second target, and a second layer of material is deposited on the razor blade edges, and the sides forming the edges. The second layer of material may be another molybdenum layer, a layer of diamond-like carbon, or another desired material. While the above patents disclose processes for providing different layers or coatings of desired durable materials on the edges, they have the disadvantage of not being able to shape the edges to a desired contour.
U.S. Pat. No. 5,032,243 discloses a method and apparatus for providing both a material deposition process and a material etching process to form and contour the sides of edges of the razor blades. A rotating workholder in a vacuum chamber has a centrally located axis of rotation extending in a direction perpendicular to a work holding surface. A stack of razor blades is symmetrically located on the work holding surface with respect to the axis of rotation so that their longitudinal edges rotate in a plane perpendicular to the axis of rotation. Two material etching sources are located on either side of and generally in front of the longitudinal edges and are mounted to rotate about an axis of rotation perpendicular to the axis of rotation of the workholder. The material etching sources have a constant radius with respect to the midpoint of a centrally located edge within the stack. Consequently, each of the ion beam etching sources is directed at an adjustable angle with respect to the vertical plane; and hence, the sides of the edges. The angle may be varied to change the shape or contour of the layer of material being deposited and/or etched on the sides of the edges, thereby changing the edges themselves. An evaporation device may be located between the two ion beam etching sources and directly in front of the stack of razor blades. The electron beam evaporation device and the two ion beam etching sources are operated to obtain a balance between a deposition and subsequent sputter removal to form a layer of a desired material having the desired physical properties.
While the above apparatus operates satisfactorily to provide the desired material coatings on the edges, it has several inherent disadvantages. First, the requirement of moving the ion beam guns is cumbersome and requires very complex and expensive control mechanisms. Second, the entirety of the ion guns must be mounted within the vacuum chamber in order to facilitate their movement. Therefore, a larger, more complex and expensive vacuum chamber must be specially designed to accommodate the moving ion beam guns. Third, the stack of razor blades is centrally located with respect to the workholder axis of rotation and the arcuately moving ion beam guns; and therefore, only a single stack of razor blades can be processed at a time. Fourth, as the number of razor blades to be processed increases and the size of the stack of razor blades grows larger, there is a physical limit on the number of razor blades and size of the stack that may be properly processed by the arcuately moving ion guns. Therefore, to process a greater number of razor blades requires that additional vacuum chambers, ion guns and evaporation devices be provided.